163 comments

  • bhouston 13 hours ago

    So the website claims:

    "Avoids bot detection and CAPTCHAs by using your real browser fingerprint."

    Yeah, not really.

    I've used a similar system a few weeks back (one I wrote myself), having AI control my browser using my logged in session, and I started to get Captcha's during my human sessions in the browser and eventually I got blocked from a bunch of websites. Now that I've stopped using my browser session in that way, the blocks eventually went away, but be warned, you'll lose access yourself to websites doing this, it isn't a silver bullet.

    • tempest_ 13 hours ago

      The caveat with these things is usually "when used with high quality proxies".

      Also I assume this extension is pretty obvious so it wont take long for CF bot detection to see it the same as playwrite or whatever else.

    • mrweasel 34 minutes ago

      There's also the whole issue of captchas being in place because people cannot be trusted to behave appropriately with automation tools.

      "Avoids bot detection and CAPTCHAs" - Sure asshole, but understand that's only in place because of people like you. If you truly need access to something, ask for an API, may you need to pay for it, maybe you don't. May you get it, maybe the site owner tells you to go pound sand and you should take that as you're behaviour and/or use case is not wanted.

      • TeMPOraL a minute ago

        Actually, the CAPTCHAs are in place mostly because of assholes like you abusing other assholes like you[0].

        Most of the automated misbehavior is businesses doing it to other businesses - in many cases, it's direct competition, or a third party the competition outsources it to. Hell, your business is probably doing it to them too (ask the marketing agency you're outsourcing to).

        > If you truly need access to something, ask for an API, may you need to pay for it, maybe you don't.

        Like you'd give it to me when you know I want it to skip your ads, or plug it to some automation or a streamlined UI, so I don't have to waste minutes of my life navigating your bloated, dog-slow SPA? But no, can't have users be invisible in analytics and operate outside your carefully designed sales funnel.

        > May you get it, maybe the site owner tells you to go pound sand and you should take that as you're behaviour and/or use case is not wanted.

        Like they have a final say in this.

        This is an evergreen discussion, and well-trodden ground. There is a reason the browser is also called "user agent"; there is a well-established separation between user's and server's zone of controls, so stop poking your nose where it doesn't belong.

        --

        [0] - Not "you" 'mrweasel personally, but "you" the imaginary speaker of your second paragraph.

    • DeathArrow 13 hours ago

      It might depend on the speed with which you click on the elements on the website.

      • SSLy 12 hours ago

        it does, CF bans my own honest to God clicks if I do them too fast.

        • michaelbuckbee 11 hours ago

          I use Vimium (Chrome extension for using keyboard control of the browser) and this happens to me as well since the behavior looks "unnatural".

          • sitkack 8 hours ago

            Must suck for people with assistive software. I get blocked on CF for now damn reason.

            • verve_rat 6 hours ago

              Yeah, I do wonder if there are any ADA implications with that?

        • omgwtfbyobbq 12 hours ago

          About five years ago, maybe more, Google started sending me captchas if I ran too many repetitive searches. I could be wrong, but it feel like most large platforms have fairly sophisticated anti-bot/scraping stuff in place.

          • what 5 hours ago

            GitHub regularly blocks me for some reason. They tell me to slow down and I’m blocked for hours. I don’t get it.

            • Tepix 2 hours ago

              Remember when github disabled searches for users who aren‘t logged in? Well, they just set the threshold for searches to 0 these days so they have de-facto disabled them again, this time avoiding the shitstorm.

            • rcakebread 5 hours ago

              Make sure you are logged in. It was blocking me after just a couple searches if not logged in.

          • clown_strike 6 hours ago

            Yandex does the same.

          • SubiculumCode 6 hours ago

            Google does the same to me: Don't they know, I keep modifying my searches because their results sucked so bad I had to try 30 times to find the piece of information I needed?

        • wordofx 2 hours ago

          I wish people would stop using CF. It’s just making the internet worse.

        • bombela 8 hours ago

          Same here. And I am also using vimium.

        • PantaloonFlames 11 hours ago

          SSLy the speed clicker

    • SkyBelow 11 hours ago

      What do you think they might be looking for that could be detected pretty quickly? I'm wondering if it is something like they can track mouse movement and calculate when a mouse is moving too cleanly, so adding some more human like noise to the mouse movement can better bypass the system. Others have mentioned doing too many actions too fast, but what about potential timing between actions. Even if every click isn't that fast, if they have a very consistent delay that would be another non-human sign.

      • tempoponet 11 hours ago

        Modern captchas use a number of tools including many of the approaches you mentioned. This why you might sometimes see a CloudFlare "I am not a robot" checkbox that checks itself and moves along before you have much time to even react. It's looking at a number of signals to determine that you're probably human before you've even checked the box.

        • dalemhurley 9 hours ago

          When I am using keyboard navigation, shortcuts and autofills, I seem to get mistaken for a bot a lot. These Captchas are really bad at detecting bots and really good at falsely labelling humans as bots.

          • diatone 18 minutes ago

            Given the volume of bots they tend to be remarkably good at detecting bots

            source: I work in a team that uses this kind of bot detection and yes, it works. And yes we do our best to keep false positives down

          • Quarrel 5 hours ago

            With AI feeding / scraping traffic to sites growing ridiculously fast, I think captchas & their equivalent are only going to be on the rise, and given the rise in so many people selling residential proxies I see, I don't doubt that measures and counter-measures on both sides are getting more and more sophisticated.

            > These Captchas are really bad at detecting bots and really good at falsely labelling humans as bots.

            As a human it feels that way to you. I suspect their false-positive rate is very low.

            Of course, you may well be right that you get pinged more because of your style of browsing, which sux.

          • magicalhippo 4 hours ago

            They're detecting patterns predominantly bots use. The fact that some humans also use them doesn't change that.

            Back when I was playing Call of Duty 4, I got routinely accused of cheating because some people didn't think it was possible to click the mouse button as fast as I did.

            To them it looked like I had some auto-trigger bot or Xbox controller.

            I did in fact just have a good mouse and a quick finger.

          • willsmith72 6 hours ago

            Well you have to have false positives or negatives. Maybe they prefer positives

  • makingstuffs an hour ago

    I don't see how an MCP can be useful for browsing the net and doing things like shopping as has been suggested. Large companies such as CloudFlare have spent millions on, and made a business from, bot detection and blocking.

    Do we suppose they will just create a backdoor to allow _some_ bots in? If they do that how long will it be before other bots impersonate them? It seems like a bit of a fad from my small mind.

    Suppose it does become a thing, what then? We end up with an internet which is heavily optimised for bots (arguably it already is to an extent) and unusable for humans?

    Wild.

    • kraftman an hour ago

      There are already plenty of services that provide residential proxies and captcha bypass pretty cheaply.

      https://brightdata.com/pricing/web-unlocker https://2captcha.com/pricing

    • TeMPOraL 24 minutes ago

      > Suppose it does become a thing, what then? We end up with an internet which is heavily optimised for bots (arguably it already is to an extent) and unusable for humans?

      As opposed to the Web we now have, which is heavily optimized for... wasting human life.

      What you're asking for, what "large companies such as CloudFlare have spent millions on", is verifying that on the other end of the connection is a web browser, and behind that web browser there is a human being that's being made to needlessly suffer and waste their limited lifespans, as they tediously work their way through the UI maze like a good little lab rat, watching ads at every turn of the corridor, while being constantly surveilled.

      Or do you believe there is some other reason why you should care about whether you're interacting with a "human" (really: an user agent called "web browser") vs. "not human" (really: any other user agent)?

      The relationship between the commercial web and its users is antagonistic - businesses make money through friction, by making it more difficult for users to accomplish their goals. That's why we never got the era of APIs and web automation for users. That's why we're dealing with tons of bespoke shitty SPAs instead of consistent interfaces - because no store wants to make it easy for you to comparison-shop, or skip their upsells, or efficiently search through the stock; no news service wants you to skip ads or make focused searches, etc.

      As users, we've lost the battle for APIs and continue to be forced to use the "manual web" (with active cooperation of the browser vendors, too). MCP feels promising because we're in a moment in time, however brief, where LLMs can navigate the "manual web" for us, shielding us from all the malicious bullshit (ads, marketing copy, funneling, call to actions, confusing design, dark patterns, less dark patterns, the fact that your store is a bloated SPA instead of an endpoint for a generic database querying frontend, and so on) while remaining mostly impervious to it. This will not last long - the vendors de-facto ruling the web have every reason to shut it down (or turn it around and use LLMs against us). But for now, it works.

      Adversarial interoperability is the name of the game. LLMs, especially combined with tool use (and right tools), make it much easier and much more accessible than ever before. For however brief a moment.

  • StevenNunez 10 hours ago

    I feel like I slept for a day and now MCPs are everywhere... I don't know what MCPs are and at this point I'm too afraid to ask.

    • jastuk 10 hours ago

      And the worst part is that it opens a pandora's box of potential exploits; https://elenacross7.medium.com/%EF%B8%8F-the-s-in-mcp-stands...

      • joshwarwick15 8 hours ago

        Most of these are not a real concern with remote servers with Oauth. If you install the PayPal MCP MCP server from im-deffo-not-hacking-you.com than https://mcp.paypal.com/sse its the same sec model as anything else online...

        The article also reeks of LLM ironically

      • halJordan 9 hours ago

        At the risk of it sounding like i support theft; the automobile, you know, enabled the likes of Bonnie and Clyde and that whole era of lawlessness. Until the fbi and crossing county lines became a thing.

        So im not sure id give up the sum total progress of the automobile just because the first decade was a bad one

    • orbital-decay 6 hours ago

      MCP is a standard to plug useful tools into AI models so they can use them. The concept looks confusingly reversed and non-obvious to a normal person, although devs don't see this because it looks like their tooling.

    • hedgehog-ai 7 hours ago

      I know what you mean, I think MCP is being widely adopted but it's not grassroots.. its a quick entry to this market by an established AI company trying to dominate the mind/market share of developers before consensus can be reached developers.

    • oulipo 9 hours ago

      It's just a way to provide a "library of methods" / API that the LLM models can "call", so basically giving them method names, their parameters, the type of the output, and what they are for,

      and then the LLM model will ask the MCP server to call the functions, check the result, call the next function if needed, etc

      Right now if you go to ChatGPT you can't really tell it "open Google maps with my account, search for bike shops near NYC, and grab their phone numbers", because all he can do is reply in text or make images

      with a "browser MCP" it is now possible: ChatGPT has a way to tell your browser "open Google maps", "show me a screenshot", "click at that position", etc

      • mattfrommars 6 hours ago

        Isn't the idea of AI agent talking to each by telling LLM model to reply say in, JSON and with some parameter value map to, say function in Python code? That in retrospect, given context {prompt} to LLM will be able to call said function code?

        Is this what 'calling' is?

      • dimitri-vs 7 hours ago

        You actually can, its called Operator and its a complete waste of time, just like 99% of agents/MCPs.

      • throwaway314155 9 hours ago

        > with a "browser MCP" it is now possible: ChatGPT has a way to tell your browser "open Google maps", "show me a screenshot", "click at that position", etc

        It seems strange to me to focus on this sort of standard well in advance of models being reliable enough to, ya know, actually be able perform these operations on behalf of the user with any sort of strong reliability that you would need for widespread adoption to be successful.

        Cryptocurrency "if you build it they'll come" vibes.

        • taberiand 7 hours ago

          I think MCPs compensate for the unreliability issue by providing a minimal and well defined interface to a controlled set of actions. That way, the llm doesn't have to be as reliable thinking what it needs to do and in acting, just in choosing what to do from a short list.

          • throwaway314155 5 hours ago

            You can provide an MCP for Pokemon Red, but Claude will still flounder for weeks, making absurd mistakes on a game literally designed for children.

            Believe me. It's not there yet.

            • taberiand 4 hours ago

              Is there an MCP for pokemon red?

              • throwaway314155 4 hours ago

                Not that im aware of, but that actually would be an interesting project.

                I was referring more broadly to ClaudePlaysPokemon, a twitch stream where claude is given tool calling into a Gameboy Color emulator in order to try to play Pokemon. It has slowly made progress and i recommend looking at the stream to see just how flawed LLM's are currently for even the shortest of timelines w.r.t. planning.

                I compared the two because the tool calling API here is a similar enough to an MCP configuration with the same hooks/tools (happy to be corrected on that though)

        • acedTrex 8 hours ago

          The speed that every major LLM foundational model provider has jumped on this bandwagon feels VERY artificial and astro turfy...

          • XCSme 8 hours ago

            Maybe because the LLM improvements haven't been that good in the last year, they needed some new thing to hype it/market it.

            EDIT: Don't get me wrong, the benchmark scores are indeed higher, but in my personal experience, LLMs make as many mistakes as they did before, still too unreliable to use for cases where you actually need a factually correct answer.

            • acedTrex 7 hours ago

              This is in my opinion exactly what it is. A bunch of people throwing stuff at the wall trying to show "impact."

  • andy_ppp 11 hours ago

    When I go to a shopping website I want to be able to tell my browser "hey please go through all the sideboards on this list and filter out for the ones that are larger than 155cm and smaller than 100cm, prioritise the ones with dark wood and space for vinyl records which are 31.43cm tall" for example.

    Is there any browser that can do this yet as it seems extremely useful to be able to extract details from the page!

    • bravura 10 hours ago

      When doing interior decoration, I am definitely interested in finding objects that fit very specific prompts.

    • mfkhalil 10 hours ago

      Hey, we’re working on MatterRank which is pretty similar to this but currently works on web search. (e.g. I want to prioritize results that talk about X and have Y bias and I want to deprioritize those that are trying to sell me something). Feel free to try it out at https://matterrank.ai

      Would also be interested in hearing more about what you’re envisioning for your use case. Are you thinking a browser extension that acts on sites you’re already on, or some sort of shopping aggregator that lets you do this, or something else entirely?

      • Niksko 4 hours ago

        Not OP but I definitely sympathise with them. I don't know how practical it is to implement or how profitable it would be, but the problem I often have is this: * I have something I want to buy and have specific needs for it (height, color, shape, other properties) * I know that there's a good chance the website I'm on sells a product that meets those needs (or possibly several such that I'd want to choose from) * my criteria are more specific than the filters available on the site e.g. I want a specific length down to a few cm because I want the biggest thing that will fit in a fixed space * crucially for an AI use case: the information exists on the individual product pages. They all list dimensions and specifications. I just don't want to have to go through them all.

        Example: find me all of the desks on IKEA that come in light coloured wood, are 55 inches wide, and rank them from deepest to shallowest. Oh, and make sure they're in stock at my nearest IKEA, or are delivering within the next week.

  • doug_life 7 hours ago

    This may be obvious to most here, but you need Node.js installed for the MCP server to run. This critical detail is not in the set up instructions.

  • thenaturalist 12 hours ago

    Crazy, in looking up some info on the web and creating a Spreadsheet on Google Sheets to insert the results, it worked almost perfectly the first time and completely failed subsequently on 8-10 different tries.

    Is there an issue with the lag between what is happening in the browser and the MCP app (in my case Claude Desktop)?

    I have a feeling the first time I tried it, I was fast enough clicking the "Allow for this chat" permissions, whereas by the time I clicked the permission on subsequent chats, the LLM just reports "It seems we had an issue with the click. Let me try again with a different reference.".

    Actions which worked flawlessly the first time (rename a Google spreadsheet by clicking on the title and inputting the name) fail 100% of subsequent attempts.

    Same with identifying cells A1, B1, etc. and inserting into the rows.

    Almost perfect on 1st try, not reproducible in 100% of attempts afterwards.

    Kudos to how smooth this experience is though, very nice setup & execution!

    EDIT 2: The lag & speed to click the allow action make it seemingly unusable in Claude Desktop. :(

    • otherayden 12 hours ago

      Such a rich UI like google sheets seems like a bad use case for such a general "browser automation" MCP server. Would be cool to see an MCP server like this, but with specific tools that let the LLM read and write to google sheets cells. I'm sure it would knock these tasks out of the park if it had a more specific abstraction instead of generally interacting with a webpage

      • mkummer 11 hours ago

        Agreed, I'd been working on a Google Sheets specific MCP last week – just got it published here: https://github.com/mkummer225/google-sheets-mcp

        • rahimnathwani 10 hours ago

          This is cool. You should submit this as a 'Show HN'.

          Also consider publishing it so people can use it without having to use git.

          • freeone3000 5 hours ago

            Publishing it where? It can’t be a github page, it’s too complex; anything else incurs real costs.

            • rahimnathwani 5 hours ago

              I mean publish it on the npm registry (https://www.npmjs.com/signup). That way, it would be easy to install, just by adding some lines to claude_desktop_config.json:

                {
                  "mcpServers": {
                    "ragdocs": {
                      "command": "npx",
                      "args": [
                        "-y",
                        "@qpd-v/mcp-server-ragdocs"
                      ],
                      "env": {
                        "QDRANT_URL": "http://127.0.0.1:6333",
                        "EMBEDDING_PROVIDER": "ollama",
                        "OLLAMA_URL": "http://localhost:11434"
                      }
                    },
                   }
                  }
                }
    • throwaway314155 8 hours ago

      What you're experiencing is commonly referred to as "luck". It's the same reason people consistently think newer versions of ChatGPT are nerfed in some way. In reality, people just got lucky originally and have unrealistic expectations based on this originally positive outcome.

      There's no bug or glitch happening. It's just statistically unlikely to perform the action you wanted and you landed a good dice roll on your first turn.

  • neilellis 14 hours ago

    Well done, just tested on Claude Desktop and it worked smoothly and a lot less clunky than playwright. This is the right direction to go in.

    I don't know if you've done it already, but it would be great to pause automation when you detect a captcha on the page and then notify the user that the automation needs attention. Playwright keeps trying to plough through captchas.

  • Gehinnn 12 hours ago

    Would be nice if it could use the Accessibility Tree from chrome dev tools to navigate the page instead of relying on screenshots (https://developer.chrome.com/blog/full-accessibility-tree)

    • mgraczyk 7 hours ago

      In fact you have it backwards. It has no screenshots at the moment, only the accessibility tree

  • nonethewiser 13 hours ago

    Stuff like this makes me giddy for manual tasks like reimbursement requests. Its such a chore (and it doesnt help our process isnt great).

    Every month, go to service providers, log in, find and download statement, create google doc with details filled in, download it, write new email and upload all the files. Maybe double chek the attachments are right but that requires downloading them again instead of being able to view in email).

    Automating this is already possible (and a real expense tracking app can eliminate about half of this work) but I think AI tools have the potential to elminate a lot of the nittier-grittier specification of it. This is especially important because these sorts of workflows are often subject to little changes.

  • amendegree 14 hours ago

    So is MCP the new RPA (Robotics Process Automation)? Like generic yahoo pipes?

    • spmurrayzzz 14 hours ago

      I just view it as a relative minor convenience, but it's not some game-changer IMO.

      The tool use / function calling thing far predates Anthropic releasing the MCP specification and it really wasn't that onerous to do before either. You could provide a json schema spec and tell the model to generate compliant json to pass to the API in question. MCP doesn't inherently solve any of the problems that come up in that sort of workflow, but it does provide an idiomatic approach for it (so there's a non-zero value there, but not much).

      • PantaloonFlames 11 hours ago

        It seems the benefit of MCP is for Anthropic to enlist the community in building integrations for Claude desktop, no?

        And if other vendors sign on to support MCP, then it becomes a self reinforcing cycle of adoption.

        • spmurrayzzz 11 hours ago

          Yea it certainly does benefit Claude Desktop to some degree, but most MCP servers are a few hundred SLOC and the protocol schema itself is only ~400 SLOC. If that was the only major obstacle standing in the way of adoption, I'd be very surprised.

          Coupled with the fact that any LLM trained for tool use can utilize the protocol, it doesn't feel like much of a moat that uniquely positions Claude Desktop in a meaningful way.

        • asabla 10 hours ago

          > And if other vendors sign on to support MCP, then it becomes a self reinforcing cycle of adoption

          This is exactly what's happening now. A good portion of applications, frameworks and actors are starting to support it.

          I've been reluctant on adopting MCP in applications until there was enough adoption.

          However, depending on your use case it may also be too complex for your use case.

        • JackYoustra 11 hours ago

          MCP is useful because anthropic has a disproportionate share of API traffic relative to its valuation and a tiny share of first-party client traffic. The best way around this is to shift as much traffic to API as possible.

          • PantaloonFlames 11 hours ago

            First party client , meaning browser? User agent or … Electron app, or , any mobile app?

            • JackYoustra 7 hours ago

              first party client as in a claude subscription will give you access (mostly app + web)

      • kmangutov 10 hours ago

        The interesting thing about MCP as a tool use protocol is the traction that it has garnered in terms of clients and servers supporting it.

    • ajcp 14 hours ago

      No, since MCP is just an interface layer it is to AI what REST API is to DPA and COM/App DLLs are to RPA.

      APA (Agentic Process Automation) is the new RPA, and this is definitely one example of it.

      • XCSme 8 hours ago

        But AI already supported function calling, and you could describe them in various ways. Isn't this just a different way to define function calling?

  • serverlessmania 14 hours ago

    Did something similar but controls a hardware synth, allowing me to do sound design without touching the physical knobs: https://github.com/zerubeus/elektron-mcp

    • dmix 14 hours ago

      Oh good idea.

      Imagine it controlling plugins remotely, have an LLM do mastering and sound shaping with existing tools. The complex overly-graphical UIs of VSTs might be a barrier to performance there, but you could hook into those labeled midi mapping interfaces to control the knobs and levels.

  • hliyan 6 hours ago

    Ideally, shouldn't this be the native experience of most "sites" on the internet? We've built an entire user experience around serving users rich, two dimensional visual content that is not machine-readable and are now building a natural language command line layer on top of it. Why not get rid of the middleware and present users a direct natural language interface to the application layer?

  • washedDeveloper 13 hours ago

    Can you add a license to your code along with open sourcing the chrome extension?

  • cadence- 13 hours ago

    Doesn't work on Windows:

    2025-04-07T18:43:26.537Z [browsermcp] [info] Initializing server... 2025-04-07T18:43:26.603Z [browsermcp] [info] Server started and connected successfully 2025-04-07T18:43:26.610Z [browsermcp] [info] Message from client: {"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0} node:internal/errors:983 const err = new Error(message); ^

    Error: Command failed: FOR /F "tokens=5" %a in ('netstat -ano ^| findstr :9009') do taskkill /F /PID %a at genericNodeError (node:internal/errors:983:15) at wrappedFn (node:internal/errors:537:14) at checkExecSyncError (node:child_process:882:11) at execSync (node:child_process:954:15)

    • namukang 13 hours ago

      Can you try again?

      There was another comment that mentioned that there's an issue with port killing code on Windows: https://news.ycombinator.com/item?id=43614145

      I just published a new version of the @browsermcp/mcp library (version 0.1.1) that handles the error better until I can investigate further so it should hopefully work now if you're using @browsermcp/mcp@latest.

      FWIW, Claude Desktop currently has a bug where it tries to start the server twice, which is why the MCP server tries to kill the process from a previous invocation: https://github.com/modelcontextprotocol/servers/issues/812

      • cadence- 12 hours ago

        It's working now with the 0.1.0 for me. But I will let you know if I experience any issues once I get updated to 0.1.1.

        Thanks, great job! I like it overall, but I noticed it has some issues entering text in forms, even on google.com. It's able to find a workaround and insert the searched text in the URL, but it would be nice if the entry into forms worked well for UI testing.

    • cadence- 13 hours ago

      I was able to make it work like this:

      1. Kill your Claude Desktop app

      2. Click "Connect" in the browser extension.

      3. Quickly start your Calude Desktop app.

      It will work 50% of the time - I guess the timing must be just right for it to work. Hopefully, the developers can improve this.

      Now on to testing :)

  • buttofthejoke 14 hours ago

    Why use this over Puppeteer or Playwright extensions?

    • namukang 14 hours ago

      The Puppeteer MCP server doesn't work well because it requires CSS selectors to interact with elements. It makes up CSS selectors rather than reading the page and generating working selectors.

      The Playwright MCP server is great! Currently Browser MCP is largely an adaptation of the Playwright MCP server to use with your actual browser rather than creating a new one each time. This allows you to reuse your existing Chrome profile so that you don't need to log in to each service all over again and avoids bot detection which often triggers when using the fresh browser instances created by Playwright.

      I also plan to add other useful tools (e.g. Browser MCP currently supports a tool to get the console logs which is useful for automated debugging) which will likely diverge from the Playwright MCP server features.

  • Fernicia 14 hours ago

    Any plans to make a Firefox version?

    • namukang 14 hours ago

      Browser MCP uses the Chrome DevTools Protocol (CDP) to automate the browser so it currently only works for Chromium-based browsers.

      Unfortunately, Firefox doesn't expose WebDriver BiDi (the standardized version of CDP) to browser extensions AFAIK (someone please correct me if I'm mistaken!), so I don't think I can support it even if I tried.

  • sdotdev 10 hours ago

    Still slightly confused on what MCPs are but looking at this it does look useful

    • aryehof 4 hours ago

      A plugin protocol that allows “applications” to interact with LLMs.

      • darepublic 3 hours ago

        wouldn't it be for LLMs to interact with applications?

    • esafak 5 hours ago

      A protocol (the P in MCP) for LLMs to use tools.

  • DebtDeflation 14 hours ago

    In the Task Automation demo, how does it know all of the attributes of the motorcycle he is trying to sell? Is it relying on the underlying LLM's embedded knowledge? But then how would it know the price and mileage? Is there some underlying document not referenced in the demo? Because that information is not in the prompt.

  • webprofusion 5 hours ago
  • icelancer 14 hours ago

    I just run into a bunch of errors on my Windows machine + Chrome when connected over remote-ssh. Extension installed, tab enabled, npx updated/installed, etc.

    2025-04-07 10:57:11.606 [info] rmcp: Starting new stdio process with command: npx @browsermcp/mcp@latest

    2025-04-07 10:57:11.606 [error] rmcp: Client error for command spawn npx ENOENT

    2025-04-07 10:57:11.606 [error] rmcp: Error in MCP: spawn npx ENOENT

    2025-04-07 10:57:11.606 [info] rmcp: Client closed for command

    2025-04-07 10:57:11.606 [error] rmcp: Error in MCP: Client closed

    2025-04-07 10:57:11.606 [info] rmcp: Handling ListOfferings action

    2025-04-07 10:57:11.606 [error] rmcp: No server info found

    ---

    EDIT: Ended up fixing it by patching index.js. killProcessOnPort() was the problem. Can hit me up if you have questions, I cannot figure out how to put readable code in HN after all these years with the fake markdown syntax they use.

    • deathanatos 13 hours ago

      > I cannot figure out how to put readable code in HN after all these years with the fake markdown syntax they use.

      Not that HN supports much in the way of markup, but code blocks are actually the same as Markdown: indent (by 2 spaces or more, in HN's syntax; Markdown calls for 4 or more, so they're compatible).

        print("Hello, world.")
    • namukang 13 hours ago

      Thanks for the report and the update! I'd love to hear about what you changed — how can I get in touch? I didn't see anything in your HN profile. Feel free to email me at admin@browsermcp.io

  • pavelfeldman 7 hours ago
  • knes 4 hours ago

    This is great. Especially debugging frontend issue on localhost or staging.

    Also works flawlessly with augment code.com too!

  • wifipunk 13 hours ago

    Setting this up for claude desktop and cursor was alright. Works well out of the box with little setup, and I like that it attached to my active browser tab. Keep up the good work.

  • BrandiATMuhkuh 14 hours ago

    This is really well done! Very cool.

    I wonder if it's possible to add such plugins to election apps (e.g.: Slack). It would be such a nice experience if I could just connect my AI of choice to a local app.

  • otherayden 12 hours ago

    I literally started working on the same exact idea last night haha. Great work OP. I'm curious, how are you feeding the web data to the LLM? Are you just passing the entire page contents to it and then having it interact with the page based on CSS selectors/xpath? Also, what are your thoughts on letting it do its own scripting to automate certain tasks?

  • lxe 8 hours ago

    This one also uses aria snapshots formatted as yaml. This will quickly exceed context limits.

  • tuananh 6 hours ago

    i want to add this for my project (which use wasm) but rustlang/socket2 WASI support is not merged yet. after that rust CDP will work.

    • toutiao6 an hour ago

      Interesting — I’ve been experimenting with MoonBit for Wasm builds, and the lack of mature WASI networking is a recurring blocker there too. The moment tools like socket2 or HTTP clients land with Preview2, we might see real “Wasm-native” browser automation.

      It’s wild to think we could one day write browser automation in a GC-backed language, compile to Wasm, and ship it without Node or Bash at all.

  • qwertox 13 hours ago

    MCP seems to be JavaScript's trojan horse into AI.

    • ketzo 13 hours ago

      "Trojan horse"? 95% of people currently access AI via web or mobile app; those are pretty JS-dominated, no?

  • rahimnathwani 14 hours ago

    This is cool. I'm curious why you chose to use an extension, rather than getting the user to run Chrome with remote debugging turned on?

    • namukang 14 hours ago

      An extension is more user-friendly! I leave Chrome open basically 24/7 and having to create a new Chrome instance via the command line just to use Browser MCP just felt like too high of a barrier.

    • hannofcart 14 hours ago

      Not OP but I suspect it is because of this (mentioned on their page):

      'Avoids bot detection and CAPTCHAs by using your real browser fingerprint.'

      • tylergetsay 14 hours ago

        I don't think remote debugging by itself on a normal chrome profile is detectable

        • omneity 13 hours ago

          Exposing Chrome CDP is a terrible idea from a security and privacy perspective. You get the keys to the whole kingdom (and expose them on a standard port with a well documented API). All security features of the web can be bypassed, and then some, as CDP exposes even more capabilities than chrome extensions and without any form of supervision.

          • redblacktree 11 hours ago

            You're talking about exposing Chrome CDP to the wider internet, right? Or are you highlighting these dangers in the local context?

            • omneity 8 hours ago

              In the local context as well. Unlike say the docker socket which is protected by default using unix permissions, the CDP protocol has no authorization, authentication or permission mechanism.

              Anything on your machine (such as a rogue browser extension or a malicious npm/pypi package) could scan for this and just get all your cookies - and that's only the beginning of your problems.

              CDP can access any origin, any data stored (localStorage, indexedDB ...), any javascript heap, cross iframe and origin boundaries, run almost undetectable code that uses your sessions without you knowing, and the list is very long. CDP was never meant to expose a real browser in an untrusted context.

        • parhamn 14 hours ago

          I'm sure its about the cookies/sessions but I do recall you can load cookies from another browser?

  • picardo 14 hours ago

    I like this. It would be interesting to use it for when I need to use authenticated browser sessions.

  • jngiam1 13 hours ago

    Pretty cool, do you know of a version of this that supports the new remote MCP protocol

  • pknerd 12 hours ago

    So why do I need an editor(Cusror)? How does a non-coder use it?

    • rahimnathwani 12 hours ago

      If you're a non-coder, use it with Claude Desktop.

  • xena 13 hours ago

    Do you respect robots.txt so administrators can block this tool?

    • canogat 12 hours ago

      Should I be blocked if I ask Claude Desktop to lower the prices in all of my Craigslist ads by 10%?

    • randunel 13 hours ago

      Do user agents doing work for users need to respect robots.txt? If yes, does chrome?

      • what 4 hours ago

        Any scraper is also a “user agent doing work for users”. Which ones should respect robots.tx?

  • cadence- 12 hours ago

    How does this compare to Anthropic's Computer Use?

  • jayunit 12 hours ago

    awesome! For the Cursor / React / Click to Add 2 example, can we also have it write a unit/e2e regression test?

  • graiz 13 hours ago

    works better than puppet mcp for me but having issues with keyboard events and actions on some websites.

  • 101008 14 hours ago

    Good, just what we needed. More bots browsing the internet. Somedays I think I am not 100% against of every website having a captcha...

    • handfuloflight 14 hours ago

      Not out of the realm of possibility that this very comment was written by a bot prompted to write a negative response to a given piece of content.

      • 101008 14 hours ago

        Not, human tired of creating content to put online and being consumed not by people but by bots or any other form of mechanical consumption that I don't like. As the owner of the content I think I have the right to set that preference, don't you think?

        • brandensilva 12 hours ago

          Yeah this is definitely a bad English bot

    • mgraczyk 14 hours ago

      It's a developer tool

      • 101008 14 hours ago

        Then it should be limited to localhost or something similar.

        • mgraczyk 13 hours ago

          It can be, just do that when you install it

        • dalemhurley 9 hours ago

          What if you are using domain names for your local environment or a cloud environment like IDX or you want to automate the testing of the UAT environment?

  • johnpaulkiser 14 hours ago

    > Private > Since automation happens locally, your browser activity stays on your device and isn't sent to remote servers.

    I think this is bullshit. Isn't the dom or whatever sent to the model api?

    • namukang 14 hours ago

      Of course, you're sending data to the AI model, but the "private" aspect is contrasting automating using a local browser vs. automating using a remote browser.

      When you automate using a remote browser, another service (not the AI model) gets all of the browsing activity and any information you send (e.g. usernames and passwords) that's required for the automation.

      With Browser MCP, since you're automating locally, your sensitive data and browser activity (apart from the results of MCP tool calls that's sent to the AI model) stay on your device.

      • johnpaulkiser 14 hours ago

        I think we need to be very careful & intentional about the language we use with these kinds of tools, especially now that the MCP floodgates have been opened. You aren't just exposing the users browsing data to which ever model they are using, you are also exposing it any tools they may be allowing as well.

        A lot of non technical people are using these tools to "vibe" their way to productivity. I would explicitly tell them that potentially "all" of their browsing data is going to be exposed to their LLM client and they need to use this at their own risk.

  • throwaway81523 12 hours ago

    Can these things automatically solve recaptcha? That's the only AI browser feature that I have a real use for.

  • mvdtnz 8 hours ago

    Is anyone successfully running MCPs / Claude Desktop on Linux?

    • iDon 3 hours ago

      I am running this OK in Ubuntu 2404 : https://github.com/aaddrick/claude-desktop-debian Claude Desktop for Debian-based Linux distributions

      From Claude I have connected to these MCP servers OK : @modelcontextprotocol/server-filesystem, @executeautomation/playwright-mcp-server.

      I have connected to OP's extension (browsermcp.io) from vsCode (and clicked 1 tab button OK), but not from Claude desktop so far (I get Cannot find module 'node:path'; which is require-d in npm/lib/cli.js; tried node 18,20,22; some suggestions here : https://medium.com/@aleksej.gudkov/error-cannot-find-module-... ).

  • revskill 8 hours ago

    Can u expose the sdk as a react component to be used inside an app ?

  • justanotheratom 11 hours ago

    neat, but instead of asking me to install browser extension, can you just bundle a browser in the MCP server?

  • tntpreneur 13 hours ago

    Thanks but idea is ok but it is not working smoothly.

  • tigrezno 13 hours ago

    this is the way

  • behnamoh 14 hours ago
    • dumansizsercan 6 minutes ago

      Competitors don’t just challenge you, they push you to deliver your best work.

    • darepublic 2 hours ago

      none of these have stuck right. And none of them work well enough that all web dev agencies no longer have to worry about e2e testing. (or do some of them? Maybe the market is simply that inefficient).

    • ajcp 13 hours ago

      I think this is noteworthy in that it is using what is increasingly becoming the dominant API protocol for LLM.

      Just because the wheel exists doesn't mean we shouldn't strive to make it better by applying new knowledge and technologies to it.

  • ndr 12 hours ago

    WARNING for Cursor users:

    Cursor is currently stuck using an outdated snapshot of the VSCode Marketplace, meaning several extensions within Cursor remain affected by high-severity CVEs that have already been patched upstream in VSCode. As a result, Cursor users unknowingly remain vulnerable to known security issues. This issue has been acknowledged but remains unresolved: https://github.com/getcursor/cursor/issues/1602#issuecomment...

    Given Cursor's rising popularity, users should be aware of this gap in security updates. Until the Cursor team resolves the marketplace sync issue, caution is advised when using certain extensions.

    I've flagged it here, apologies for the repost: https://news.ycombinator.com/item?id=43609572

    • rs186 12 hours ago

      I am surprised that the VSCode team hasn't gone after them for mirroring the marketplace, as the Visual Studio team made it very clear that they don't want anybody to do that -- it is their marketplace.

      • SSLy 12 hours ago

        It seems that there is one sane PM left at VScode who knows that such move would only lead to MSFT losing more PR. And anti-trust scrutiny?